In order to improve fidelity of the simulation system and meet the real-time requirements, a 3D model of inertial platform was built up with MultiGen Creator software. The technique details such as optimization of hiberarchy, detail hierarchy model, instance and DOF are researched and put into use. Finally compared with the original model data, an analysis of the parameters was made. And the results show that the model completed in this way could run efficiently and smoothly while providing reasonable fidelity.